Speculation about the 30-year-old leaving has been around since the summer, with fellow Bundesliga side Bayern Munich and super-rich Russian club FC Anzhi Makhachkala also apparently interested.

It's a move that would certainly be great for Bayer Leverkusen, but not for the Red Devils or the former Bulgaria international.

United's financial credibility would take a big hit, seeing as they would not be likely to recoup any more than 50 percent of the £30.75 million they paid Tottenham Hotspur for Berbatov in 2008—rather poor for a player who was the Premier League's top scorer only last season.

At least if Berbatov stayed for another season or two, it would give a bigger impression that he's helped them win a few more titles and thus made a bigger contribution to earning the club more prize and sponsorship money, as well as a better brand equity.

In a time when Manchester United are seeking investment, which is all the more important with UEFA's Financial Fair Play rules taking effect, selling Berbatov now wouldn't smack of a club getting the best return for their purchases—something quite important given the striker's huge fee.

But aside from discouraging potential investors, selling the forward could be bad for on-the-pitch reasons.

"Berba," as he's known to fans and teammates, has scored eight goals in 16 games this season, and six from nine in the Premier League.

That tally is more impressive since it comes in just four starts. Berbatov's six goals in four starts are an indicator that the striker is damn good when given the chance.

He has the same number of league goals as Javier Hernandez, who's made double the league appearances and almost triple the starts Berbatov has. Berbatov is not performing badly at all, and he could be vital for Manchester United in the Premier League title race.

Yes, he's not going to make the same impact as a Wayne Rooney, Danny Welbeck or Nani, but when he plays against the weaker defences, Berbatov can score in places no other striker can.

Rooney, Hernandez and Welbeck all have the talent to beat any defence; Berbatov has always lacked that, but what he has on everyone else is that imagination and creativity to find different ways to exploit a particularly weak defence.

In essence, he's one of the best flat-track bullies in world football—a trait that catapulted United to a historic 19th Premier League trophy last season but that has been missing this campaign.

And as free-scoring Manchester City have proven, points aren't the only issue in the title race—goal difference could play a major factor too.

United need to keep up with City in that department, as it is very likely the title could be decided on goals.

What's the best way of doing that? Keep Berbatov in the rotation policy.

Plus, with all the youngsters currently making their way at the club, who better to learn from each day at Carrington than the man who is quite possibly the most naturally skillful player on earth?

Dimitar Berbatov has been, and still is, a vital part of Manchester United.

If Sir Alex Ferguson sanctioned his departure now, he'd get a better fee for the striker (boosting his own transfer history and ego), but possibly less financial return, and a gap in his strike force that would be filled by the hugely unreliable Michael Owen.